It would be interesting to see if this work could be extended in a way similar to the quantum schemes that have been developed in recent years. For example, is it possible to have a purely classical verification scheme in the GPT setting?
Would it be possible to have a store merchant be able to verify the money without the need of involving the bank?
Both of these are possible in the quantum setting, see [1]} and [2]}, respectively.
These scenarios are interesting, but add to the complexity of the problem considerably. As this work shows that GPT money is indeed physically possible in many theories, it paves the way to look at these more elaborate scenarios which are more convenient for the bank.
